Deficiency of platelet-derived growth factor receptor-α-positive cells in Hirschsprung's disease colon

AIM: To investigate whether the expression of plateletderived growth factor receptor-α-positive(PDGFRα^+)-cells is altered in Hirschsprung's disease(HD).METHODS: HD tissue specimens(n = 10) were collected at the time of pull-through surgery, while colonic control samples were obtained at the time of colostomy closure in patients with imperforate anus(n = 10). Immunolabelling of PDGFRα^+-cells was visualized using confocal microscopy to assess the distribution of these cells, while Western blot analysis was undertaken to quantify PDGFRα protein expression.RESULTS: Confocal microscopy revealed PDGFRα+-cells within the mucosa, myenteric plexus and smooth muscle in normal controls, with a marked reduction in PDGFRα^+-cells in the HD specimens. Western blotting revealed high levels of PDGFRα protein expression in normal controls, while there was a striking decrease in PDGFRα protein expression in the HD colon.CONCLUSION: These findings suggest that the altered distribution of PDGFRα^+-cells in both the aganglionic and ganglionic HD bowel may contribute to the motility dysfunction in HD.

Vascular endothelial growth factor/platelet-derived growth factor receptor pathway is involved in bone marrow mesenchymal stem cell differentiation and directional migration toward gliomas

BACKGROUND： Vascular endothelial growth factor （VEGF） induces bone marrow-derived mesenchymal stem cell （BMSC） differentiation into vascular endothelial-like cells and promotes BMSC migration toward gliomas. However, the molecular mechanisms by which VEGF induces BMSC differentiation and migration remain poorly understood. OBJECTIVE; To investigate the role of platelet-derived growth factor （PDGF） receptor （PDGFR） in BMSC differentiation and migration induced by VEGE DESIGN, TIME AND SETTING： A parallel, controlled, in vitro experiment was performed at the Molecular Neurobiology ＆ Neural Regeneration and Repairing Laboratory, Anhui Provincial Hospital of Anhui Medical University, China from June 2008 to March 2009. MATERIALS： U87 glioma cells were purchased from Shanghai Institutes for Biological Sciences; mouse anti-human PDGFR and VEGF receptor （VEGFR） monoclonal antibodies were purchased from Peprotech, USA. METHODS： Isolated BMSCs were precultured with neutralizing antibody for VEGFR-1, VEGFR-2, PDGFR-α, and PDGFR-β to block biological activity of related receptors, followed by induced differentiation with 50μg/L VEGF. BMSCs induced with 50μg/L VEGF alone served as the VEGF-induced group. The control group remained untreated. MAIN OUTCOME MEASURES： Cell surface markers were identified by flow cytometry; BMSC surface cytokine receptor expression was detected by reverse transcription-polymerase chain reaction; the Transwell model was used to observe cell migration. RESULTS： After blocking the PDGFR, VEGF did not induce BMSC cell surface marker CD-31 or von Willebrand factor （vWF） expression. However, inhibition with VEGF receptor blocking agents, VEGF induced BMSCs to express CD-31 and vWE Following inhibition of the PDGFR, the number of cells migrating through the polycarbonate membrane Transwell chamber was decreased, as well as the number of BMSCs migrating to glioma cells. However, through the use of VEGF receptor blocking agents, the number of migrating cells remained unchanged. VEGF preculture increased the number of BMSCs migrating to gliomas. CONCLUSION： VEGF interacts with PDGFRs on the BMSC surface to attract BMSC directional migration and induce BMSC differentiation. The VEGF/PDGFR pathway participates in BMSC directional migration to glioma. VEGF pretreatment increased efficiency of BMSC migration to glioma.

KIT and platelet-derived growth factor receptor α wild-type gastrointestinal stromal tumor associated with neurofibromatosis type 1: Two case reports

BACKGROUND Gastrointestinal stromal tumors(GISTs) associated with neurofibromatosis are uncommon compared to their gastrointestinal counterparts. Patients with neurofibromatosis type 1(NF-1) have an increased risk of developing gastrointestinal tumors, including rare types such as GIST.CASE SUMMARY A 60-year-old male Chinese patient was diagnosed with NF-1 10 years ago and presented with upper abdominal discomfort and black stools. Endoscopic ultrasonography and an enhanced abdominal computed tomography scan revealed a mass located 4 cm from the muscular layer of the descending duodenum. A 59-year-old Chinese woman who was diagnosed with NF-1 25 years ago presented with sudden unconsciousness and black stools. Multiple masses in the duodenum were noted by echogastroscopy and an enhanced abdominal computed tomography scan. Both patients presented with cutaneous neurofibromas. The histologic examination of tumors from both patients revealed spindle cells and low mitotic activity. Immunohistochemically, the tumor cells showed strong positivity for KIT(CD117), DOG-1, CD34, and Dehydrogenase Complex Subunit B, and negativity for SMA, desmin, S-100, and β-catenin. None of the six tumors from two patients had KIT exon 9, 11, 13, or 17 or platelet-derived growth factor receptor α exon 12 or 18 mutation, which is a typical finding for sporadic GISTs. None of the six tumors from the two patients had a BRAFV600 E mutation. The patients were alive and well during the follow-up period(range:0.6-5 yr).CONCLUSION There have been only a few previous reports of GISTs associated with NF-1.Although GISTs associated with NF-1 have morphologic and immunohistochemical similarities with GISTs, the pathogenesis, incidence,genetic background, and prognosis are not completely known. A medical history of NF-1 in a patient who has gastrointestinal bleeding or anemia and an intraabdominal mass with nonspecific computed tomography features may help in diagnosing GIST by virtue of the well-known association of these two entities.Molecular genetic studies of cases indicated that GISTs in NF-1 patients have a different pathogenesis than sporadic GISTs.

Gene expression of hepatocyte growth factor and its receptor in HCC and nontumorous liver tissues

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Association of vascular endothelial growth factor-634G/C and receptor for advanced glycation end products G82S gene polymorphisms with diabetic retinopathy

AIMTo investigate the association of receptor for advanced glycation end products (RAGE) G82S and vascular endothelial growth factor (VEGF) -634 G/C gene polymorphisms with diabetic retinopathy (DR).METHODSOur cross-sectional study included 61 diabetic patients, 12 of them had proliferative diabetic retinopathy (PDR), 15 had non proliferative diabetic retinopathy (NPDR), 34 had no diabetic retinopathy (NDR) and 61 healthy controls. Participants were tested for RAGE G82S and VEGF -634 G/C polymorphisms by polymerase chain reaction-restriction fragment length polymorphism.RESULTSWe found a significant association between VEGF -634 G/C polymorphism and PDR as PDR patients had increased incidence of VEGF -634 CC genotype compared to NDR patients [odds ratio for CC vs (GC+GG)=6.5, 95% CI=1.5-27.8, P=0.021]. Also VEGF -634 CC genotype and C allele were significantly higher in the PDR than in NPDR patients, which is a novel finding in our study (P=0.024, 0.009 respectively). The mean triglycerides level was significantly higher in diabetic patients with CC genotype (P=0.01) as compared to patients with other genotypes. All cases and control subjects were of the same heterozygous RAGE 82G/S genotype.CONCLUSIONPatients carrying VEGF -634 C polymorphism have a higher risk of PDR development, so VEGF -634 G/C polymorphism could be used as a predictive marker for PDR in diabetic patients. We could not find a significant association between RAGE G82S polymorphism and DR.

SIMULTANEOUS OVER-EXPRESSION OF INSULIN-LIKE GROWTH FACTOR- Ⅱ (IGF- Ⅱ ) AND IGF- Ⅱ RECEPTOR(IGF- Ⅱ R) GENES IN HUMAN PRIMARY CANCER-IMPLICATION OF AUTOCRINE AND PARACRINE MECHANISM IN AUTONOMOUS GROWTH OF HEPATIC CANCER

This is first report about the simultaneous over-expression of both Insulin-like growth factor (IGF- I ) and its receptor (IGF- I R) at mRNA level in human primary hepatic Cancer (PHC). In 10 PHC samples from China, IGF-I and IGF- I R were both over-expressed, whereas only a background signal was detected in normal liver. In 5 pairs of PHC and its non- tumorous adjacent liver tissues from South Africa, IGF- I and IGF- I R were also over-expressed in PHC. mRNA expression of IGF- I in all 5 cases and IGF- I R in 4 of 5 cases were higher in cancer than non- tumorous adjacent liver tissues. These results strongly implicate that an autocrine and/ or paracrine mechanism might be Involved in formation and progression of PHC.

Enhanced expression of epidermal growth factor receptor gene in gastric mucosal cells by the serum derived from rats treated with electroacupuncture at stomach meridian acupoints

AIM: To investigate the effect of serum derived from rats treated with electroacupuncture at stomach meridian acupoints on the expression of epidermal growth factor receptor (EGFR) gene in gastric mucosal cells. METHODS: The stress-induced gastric mucosal injury in rat model was established by water-immersion and restrained stress methods. 52 rats were randomly divided into: normal group (n = 8), model group (n = 8), model serum group (n = 12), stomach serum group (n = 12), and gallbladder serum group (n = 12). The gastric mucosal cells were separated by pronase-EDTA digestion method and incubated with serum. The EGFR gene expression in gastric mucosal cells was detected by reverse transcription-polymerase chain reaction (RT-PCR) method. RESULTS: Compared with normal group (0.6860 ± 0.0594), the serum derived from rats of the stomach group (1.2272 ± 0.0813, P = 0.00 < 0.01) and gallbladder group (0.9640 ± 0.0387, P = 0.00 < 0.01) had a tendency to enhance the EGFR gene expression in gastric mucosal cells. Such tendency existed in the model group (0.7104 ± 0.0457) but with no signifi cant difference (P = 0.495 > 0.05) and in model serum group (0.8516 ± 0.0409) with an extremely obvious difference (P = 0.001 < 0.01). Furthermore, the EGFR gene expression in stomach serum group was significantly higher than that in gallbladder serum group (P = 0.00 < 0.01). CONCLUSION: The present study shows that serumderived from rats treated with electroacupuncture at stomach meridian acupoints can distinctly increase the EGFR gene expression of gastric mucosal cells. Therefore, there is certain meridian specificity in the serum, which could provide a proof for the TCM theory “particular relation between meridian and internal organ”.

Relationship between epidermal growth factor receptor gene mutation and copy number in Chinese patients with non-small cell lung cancer

Epidermal growth factor receptor(EGFR) gene mutation and copy number are useful predictive markers that guide the selection of non-small cell lung cancer(NSCLC) patients for EGFR-targeting therapy.This study aimed to investigate the correlation between EGFR gene mutation and copy number and clinicopathologic characteristics of Chinese patients with NSCLC.NSCLC specimens collected from 205 patients between November 2009 and January 2011 were selected to detect EGFR gene mutations with real-time polymerase chain reaction(RT-PCR) and to detect EGFR gene copy number with fluorescence in situ hybridization(FISH).EGFR mutations primarily occurred in females,non-smokers,and patients with adenocarinomas(all P < 0.001).Tissues from 128(62%) patients were FISH-positive for EGFR,including 37(18%) with gene amplification and 91(44%) with high polysomy.EGFR gene mutation was correlated with FISH-positive status(R = 0.340,P < 0.001).Multivariate analysis showed that not smoking(OR = 5.910,95% CI = 2.363-14.779,P < 0.001) and having adenocarcinoma(OR = 0.122,95% CI = 0.026-0.581,P = 0.008) were favorable factors for EGFR gene mutation.These results show a high frequency of EGFR FISH positivity in NSCLC tissues from Chinese patients and a significant relevance between EGFR gene mutations and FISH-positive status.Among the FISH-positive samples,EGFR gene mutation occurred more frequently in samples with gene amplification compared to those with high polysomy,suggesting that EGFR mutation and gene amplification should be used as clinical decision parameters to predict response to EGFR-targeting therapy.

Associations Between Epidermal Growth Factor Receptor Gene Mutation and Serum Tumor Markers in Advanced Lung Adenocarcinomas: A Retrospective Study

Objective To investigate the associations between epidermal growth factor receptor(EGFR) gene mutations and serum tumor markers in advanced lung adenocarcinomas. Methods We investigated the association between EGFR gene mutations and clinical features, including serum tumor marker levels, in 97 advanced lung adenocarcinomas patients who did not undergo the treatment of EGFR tyrosine kinase inhibitors. EGFR gene mutation was detected by real-time PCR at exons 18, 19, 20, and 21. Serum tumor marker concentrations were analyzed by chemiluminescence assay kit at the same time. Results EGFR gene mutations were detected in 42(43%) advanced lung adenocarcinoma patients. Gender(P=0.003), smoking status(P=0.001), and abnormal serum status of carcinoembryonic antigen(CEA, P=0.028) were significantly associated with EGFR gene mutation incidence. Multivariate analysis showed the abnormal CEA level in serum was independently associated with the incidence of EGFR gene mutation(P=0.046) with an odds ratio of 2.613(95% CI: 1.018-6.710). However, receiver operating characteristic(ROC) curve analysis revealed CEA was not an ideal predictive marker for EGFR gene mutation status in advanced lung adenocarcinoma(the area under the ROC curve was 0.608, P=0.069). Conclusions EGFR gene mutation status is significantly associated with serum CEA status in advanced lung adenocarcinmoas. However, serum CEA is not an ideal predictor for EGFR mutation.

Expression of NG2 and platelet-derived growth facto receptor alpha in the developing neonatal rat brain

Platelet-derived growth factor receptor alpha （PDGFRct） is a marker of oligodendrocyte precursor cells in the central nervous system. NG2 is also considered a marker of oligodendrocyte precursor cells. However, whether there are differences in the distribution and morphol- ogy of oligodendrocyte precursor cells labeled by NG2 or PDGFRa in the developing neonatal rat brain remains unclear. In this study, by immunohistochemical staining, NG2 positive （NG2＋） cells were ubiquitous in the molecular layer, external pyramidal layer, internal pyramidal layer, and polymorphic layer of the cerebral cortex, and corpus callosum, external capsule, piriform cortex, and medial septal nucleus. NG2~ cells were stellate or fusiform in shape with long processes that were progressively decreased and shortened over the course of brain development. The distribution and morphology of PDGFRct positive （PDGFRa＋） cells were coincident with NG2＋ cells. The co- localization of NG2 and PDGFRu in the cell bodies and processes of some cells was confirmed by double immunofluorescence labeling. Moreover, cells double-labeled for NG2 and PDGFRa were predominantly in the early postnatal stage of development. The numbers of NG2＋/PDGFRa＋ cells and PDGFRa＋ cells decreased, but the number of NG2＋ cells increased from postnatal days 3 to 14 in the developing brain. In addition, amoeboid microglial cells of the corpus callosum, newborn brain macrophages in the normal developing brain, did not express NG2 or PDGFRu, but NG2 expression was detected in amoeboid microglia after hypoxia. The present results suggest that NG2 and PDGFRct are specific markers of oligodendrocyte precursor cells at different stages during early development. Additionally, the NG2 protein is involved in inflammatory and pathological processes of amoeboid microglial cells.

Myeloid neoplasm with eosinophilia and rearrangement of plateletderived growth factor receptor beta gene in children: Two case reports

BACKGROUND Myeloid neoplasm(MN)with eosinophilia and rearrangement of platelet-derived growth factor receptor beta(PDGFRB)shows a good therapeutic response to imatinib in adults.MN is rarely found in children,and the efficacy of imatinib on pediatric patients remain unclear.CASE SUMMARY We report 2 pediatric cases diagnosed with MN with eosinophilia and PDGFRB rearrangement who were treated with imatinib.Case 1 was a 1-year-old girl admitted to the hospital because of“abdominal distension with hyperleukocytosis for 3 mo”.She had leukocytosis,anemia,and eosinophilia(the absolute eosinophil count(AEC)was 8960/μL),and her fluorescence in situ hybridization(FISH)test revealed that PDGFRB rearrangement was detected in 70%of 500 interphase cells.Case 2 was a 2-year-old girl admitted to the hospital because of“recurrent fever and rashes for 1 mo”.Her blood cell count showed an AEC of 3540/μL.The FISH test revealed that PDGFRB rearrangement was detected in 71%of 500 interphase cells.Both patients were diagnosed as MN with eosinophilia and PDGFRB rearrangement.Imatinib was added into their treatment regimen.As expected,complete hematologic remission was achieved after 1 mo of treatment,and symptoms disappeared.CONCLUSION Although MN with eosinophilia and PDGFRB rearrangement usually occurs in adults,it can be found in children.The therapeutic benefits of imatinib in these 2 pediatric patients were consistent with its reported effects in adult patients.

Correlation of human epidermal growth factor receptor 2 expression with clinicopathological characteristics and prognosis in gastric cancer

AIM:To investigate human epidermal growth factor receptor 2(HER2) gene amplification and protein expression in Chinese patients with resectable gastric cancer and the association with clinicopathological characteristics and survival.METHODS:One hundred and ninety-seven gastric cancer patients who underwent curative surgery procedures were enrolled into this study.HER2 gene amplification and protein expression were examined using fluorescence in-situ hybridization(FISH) and immunohistochemistry(IHC) analysis on formalin-fixed paraffinembedded gastric cancer samples from all patients.For scoring,Hofmann's HER2 gastric cancer scoring system was adopted.All cases showing IHC3+ or FISH positiv-ity were defined as HER2 positive.Patient clinicopathological data and survival information were collected.Finally,χ 2 statistical analysis was performed to analyze the HER2 positivity rate amongst the subgroups with different clinicopathological characteristics including;gender,age,tumor location,Lauren classification,differentiation,TNM staging,depth of invasion,lymph node metastases and distant metastasis.The probability of survival for different subgroups with different clinicopathological characteristics was calculated using the Kaplan-Meier method and survival curves plotted using log rank inspection.RESULTS:According to Hofmann's HER2 gastric cancer scoring criteria,31 cases(15.74%) were identified as HER2 gene amplified and 19 cases(9.64%) were scored as strongly positive for HER2 membrane staining(3+),25 cases(12.69%) were moderately positive(2+) and 153 cases(77.66%) were HER2 negative(0/1+).The concordance rate between IHC and FISH analyses was 88.83%(175/197).Thirty-six cases were defined as positive for HER2 gene amplification and/or protein expression,with 24 of these cases being eligible for Herceptin treatment according to United States recommendations,and 29 of these cases eligible according to EU recommendations.Highly consistent results were detected between IHC3+,IHC0/1 and FISH(73.68% and 95.42%),but low consistency was observed between IHC2+ and FISH(40.00%).The positivity rates in intestinal type and well-differentiated gastric cancer were higher than those in diffuse/mixed type and poorly-differentiated gastric cancer respectively(28.57% vs 13.43%,P = 0.0103;37.25% vs 11.64%,P < 0.0001),but were not correlated with gender,age,tumor location or TNM stage,depth of invasion,lymph node metastases and distant metastasis.In poorly-differentiated gastric cancer patients,those without lymph node metastasis showed a higher HER2 positivity rate than those with lymph node metastasis(26.47% vs 7.14%,P = 0.0021).This association was not present in thosepatients with well-differentiated gastric cancer(28.57% vs 43.33%,P = 0.2832).Within our patient cohort,26 cases were lost to follow-up.The median survival time for the remaining 171 patients was 18 mo.The median survival times of the HER2 positive and negative groups were 17 and 18.5 mo respectively.Overall survival was not significantly different between HER2-positive and negative groups(χ 2 = 0.9157,P = 0.3386),but in patients presenting well-differentiated tumors,the overall survival of the HER2-positive group was significantly worse than that of the HER2-negative group(P = 0.0123).In contrast,patients with poorly differentiated and diffuse/mixed subtype gastric cancers showed no significant differences in overall survival associated with HER2.Furthermore,the median survival time of the HER2 positive group did not show any statistically significant differences when compared to the subgroups of gender,age,tumor location,TNM classification,lymph node metastases and distant metastasis.CONCLUSION:Patients with intestinal type gastric cancer(GC),well-differentiated GC and poorly-differentiated GC without lymph node metastasis,may all represent suitable candidates for targeted therapy using Herceptin.

Human epidermal growth factor receptor type 2 protein expression in Chinese metastatic prostate cancer patients correlates with cancer specific survival and increases after exposure to hormonal therapy

Aim： To investigate human epidermal growth factor receptor type 2 （HER2） protein expression and gene amplification in Chinese metastatic prostate cancer patients and their potential value as prognostic factors. Methods： Immunohistochemistry （IHC） was performed to investigate HER2 protein expression in prostate biopsy specimens from 104 Chinese metastatic prostate cancer patients. After 3-11 months of hormonal therapy, 12 patients underwent transurethral resection of the prostate （TURP）. HER2 protein expression of TURP specimens was compared with that of the original biopsy specimens. Of these, 10 biopsy and 4 TURP specimens with HER2 IHC staining scores ≥ 2＋ were investigated for HER2 gene amplification status by fluorescent in situ hybridization （FISH）. Results： Of the 104 prostate biopsy specimens, HER2 protein expression was 0, 1＋, 2＋ and 3＋ in 49 （47.1%）, 45 （43.3%）, 8 （7.7%） and 2 （1.9%） cases, respectively. There was a significant association between HER2 expression and Gleason score （P = 0.026）. HER2 protein expression of prostate cancer tissues increased in 33.3% of patients after hormonal therapy. None of the 14 specimens with HER2 IHC scores 〉 2＋ showed HER2 gene amplification. Patients with HER2 scores 〉 2＋ had a significantly higher chance of dying from prostate cancer than those with HER2 scores of 0 （P = 0.004） and 1＋ （P = 0.034）. Multivariate Cox regression analysis showed that HER2 protein expression intensity was an independent predictor of cancer-related death （P = 0.039）. Conclusion： An HER2 IHC score 〉 2＋ should be defined as HER2 protein overexpression in prostate cancer. Overexpression of HER2 protein in cancer tissue might suggest an increased risk of dying from prostate cancer. HER2 protein expression increases in some individual patients after hormonal therapy.

siRNA epidermal growth factor receptor silencing in U251 glioma cells

BACKGROUND： Dicer, a large multidomain ribonuclease, is responsible for processing double-stranded RNAs （dsRNAs） to 20-bp-long small interfering RNAs （siRNAs）, which act as effectors during RNA interference （RNAi）. OBJECTIVE： To observe the efficacy of siRNA cocktails generated by recombinant human Dicer on the down-regulation of epidermal growth factor receptor （EGFR） expression in human glioma cells. DESIGN, TIME AND SETTING： The following in vitro experiment was performed at the Department of Neurosurgery, Tianjin Medical University General Hospital and Laboratory of Neuro-Oncology, Tianjin Neurological Institute. MATERIALS： Mini-RNA isolation kit, human placenta complimentary DNA （cDNA） was produced by Tiangen Biotech （Beijing, China）, human glioblastoma U251-MG cells were produced by the Institute of Biochemistry and Cell Biology, Chinese Academy of Sciences. METHODS： A PCR product from the human EGFR, which corresponded to the tyrosine kinase domain of the 3＇-end fragment, was used as the T7-promotor for in vitro transcription. siRNA cocktails were generated by in vitro dicing of double stranded RNA. A total of 500, 250 and 125 μg siRNA cocktails were transiently transfected into U251 glioma cells through the use of the GeneSilencer. MAIN OUTCOME MEASURE： Expression of EGFR was detected by real-time PCR. RESULTS： The total PCR product of the human EGFR, corresponding to the tyrosine kinase domain, is approximately 680 bp in length. The PCR transcriptants included GCC leader sequences and a T7 promoter sequence, with a fragment of EGFR cDNA at the center. The T7 promoter was prepared for in vitro transcription of dsRNA. After dicing for 24 hours, the 21-nt siRNA cocktails were verified by 4% agarose gel. The difference between threshold cycle of a sample assay and threshold cycle of the corresponding endogenous reference （ΔCt） among parental U251 cells and cells transfected with different doses of siRNA cocktails were determined to be 3.06, 7.35, and 10.31 cycles, respectively. These results indicated effective silencing of EGFR expression by siRNA cocktails through transient transfection. CONCLUSION： The siRNA cocktails significantly suppressed exogenous expression of EGFR in U251 glioblastoma cells in a dose-dependent manner, thereby providing a more promising RNAi methodology for glioma therapy.

Expression of vascular endothelial growth factor and its role in oncogenesis of human gastric carcinoma

AIM To establish the role of vascular endothelial growth factor (VEGF) in the oncogenesisof human gastric carcinoma more directly.METHODS The expression of VEGF and its receptor kinase-domain insert containing receptor (KDR) in human gastric cancer tissue were observed by immunohistochemical staining. VEGF levels were manipulated in human gastric cancer cell using eukaryotic expression constructs designed to express the complete VEGF165 complimentary DNA in either the sense or antisense orientation. The biological changes of the cells were observed in which VEGF was up-regulated or downregulated.RESULTS VEGF-positive rate was 50%, and VEGF was mainly localized in the cytoplasm and membrane of the tumor cells, while KDR was mainly located in the membrane of vascular endothelial cells in gastric cancer tissues and peri-cancerous tissue. In 2 cases of 50 specimens, the gastric cancer cells expressed KDR,localized in both the cytoplasm and membrane.Introduction of VEGF165 antisense into human gastric cancer cells ( SGC-7901, immunofluorescence intensity,31.6%)) resulted in a significant reduction in VEGFspecific messenger RNA and total and cell surface VEGF protein ( immunofluorescence intensity, 8.9%)(P＜0.05). Conversely, stable integration of VEGF165 in the sense orientation resulted in an increase in cellular and cell surface VEGF (immunofluorescence intensity,75.4%) (P＜0.05). Lowered VEGF levels were associated with a marked decrease in the growth of nude mouse xenografted tumor (at 33 days postimplantation, tomor volume: 345.40 ± 136.31 mm3) (P＜0.05 vs control SGC7901 group: 1534.40 ± 362.88 mm3), whereas up-regulation of VEGF resulted in increased xenografted tumor size (at 33 days postimplantation, tomor volume: 2350.50 ± 637.70mm3) (P＜0.05 vs control SGC-7901 group).CONCLUSION This study provides direct evidence that VEGF plays an important role in the oncogenesis of human gastric cancer.

Overexpression of insulin-like growth factor-Ⅰ receptor as a pertinent biomarker for hepatocytes malignant transformation

AIM:To investigate the dynamic features of insulinlike growth factor-Ⅰreceptor(IGF-ⅠR)expression in rat hepatocarcinogenesis,and the relationship between IGF-ⅠR and hepatocytes malignant transformation at mRNA or protein level.METHODS:Hepatoma models were made by inducing with 2-fluorenylacetamide(2-FAA)on male SpragueDawley rats.Morphological changes of hepatocytes were observed by pathological Hematoxylin and eosin staining,the dynamic expressions of liver and serum IGF-ⅠR were quantitatively analyzed by an enzymelinked immunosorbent assay.The distribution of hepatic IGF-ⅠR was located by immunohistochemistry.The fragments of IGF-ⅠR gene were amplified by reverse transcription-polymerase chain reaction,and confirmed by sequencing.RESULTS:Rat hepatocytes after induced by 2-FAA were changed dynamically from granule-like degeneration,precancerous to hepatoma formation with the progressing increasing of hepatic mRNA or IGF-ⅠR expression.The incidences of liver IGF-ⅠR,IGF-ⅠR mRNA,specific IGF-ⅠR concentration(ng/mg wet liver),and serum IGF-ⅠR level(ng/mL)were 0.0%,0.0%,0.63±0.17,and 1.33±0.47 in the control;50.0%,61.1%,0.65±0.2,and 1.51±0.46 in the degeneration;88.9%,100%,0.66±0.14,and 1.92±0.29 in the precancerosis;and 100%,100%,0.96±0.09,and2.43±0.57 in the cancerous group,respectively.IGF-ⅠR expression in the cancerous group was significantly higher(P<0.01)than that in any of other groups at mRNA or protein level.The closely positive IGF-ⅠR relationship was found between livers and sera(r=0.91,t=14.222,P<0.01),respectively.CONCLUSION:IGF-ⅠR expression may participate in rat hepatocarcinogenesis and its abnormality should be an early marker for hepatocytes malignant transformation.

Signaling pathways involved in the inhibition of epidermal growth factor receptor by erlotinib in hepatocellular cancer

瞄准：在肝细胞癌(HCC ) 检验导致 erlotinib 的生长抑制的内在的机制。方法：在基因表示的导致 Erlotinib 的改变用 cDNA 数组技术被评估；在蛋白质表示或蛋白质激活的变化用西方的弄污由于象 IGF-1-induced EGFR transactivation 一样的 erlotinib 治疗被调查。结果：Erlotinib 治疗禁止了 mitogen 激活和抄写(STAT ) 的激活的蛋白质(地图)-kinase 小径和信号变换器调停了表明哪个导致了调整由 cDNA 数组技术示威了的基因的 apoptosis 和房间周期的一个改变的表达式。象与象 Bcl-2， Bcl-X (L) 或 jun D 一样的 antiapoptotic 因素的一条下面规定联系的 caspases 和 gadds 一样的 proapoptotic 因素的 Overexpression 说明了让 erlotinib 的力量导致 apoptosis。支持 G1/S-transition 的房间周期管理者并且在 cyclin 依赖的激酶禁止者和 gadds 的表示上的 Downregulation 响应 erlotinib 贡献了 G1/G0-arrest 的正式就职。而且，我们显示了由 IGF-1-receptor 的调停 EGFR 的发信号的 transactivation 并且在受体受体十字谈话显示出 erlotinib 的禁止的效果。结论：我们的学习在 HCC 房间和 thus 使 EGFR-TK-inhibition 的行动的机制的理解清楚些可能便于 additively 或 synergistically 行动的联合治疗的设计。而且，我们对 erlotinib 处理作出回应的小径上的数据能在以后预言肿瘤的应答的海角到 EGFR-TKIs 是有用的。

Expression of thymidine kinase mediated by a novel non-viral delivery system under the control of vascular endothelial growth factor receptor 2 promoter selectively kills human umbilical vein endothelial cells

AIM: To investigate the killing efficiency of a recombinant plasmid containing a thymidine kinase (TK) domain insert driven by the vascular endothelial growth factor receptor 2 (VEGFR2) promoter (KDR) on vascular endothelial cells.METHODS: The KDR-TK fragment was extracted from pBluescript Ⅱ KDR-TK plasmid by enzymatic digestion with Xho I and Sal I. The enhanced green fluorescence protein (EGFP) carrier was extracted from pEGFP by the same procedure. The KDR-TK was inserted into the pEGFP carrier to construct pEGFP-KDR-TK. Using ultrasound irradiation and microbubble, pEGFP-KDR-TK was transferred into human umbilical vein endothelial cells (HUVECs). The transient infection rate was estimated by green fluorescent protein (GFP) expression. Transfected HUVECs, non-transfected HUVECs, and HepG2 cells were cultured in the presence of different concentrations of ganciclovir (GCV), and the killing efficacy of HSV-TK/GCV was analyzed by 3-[4, 5-dimethylthiazol-2-yl]-2, 5-diphenyl tetrazolium bromide (MTT) assay. RESULTS: The recombinant pEGFP-KDR-TK was successfully constructed by inserting the KDR-TK fragment into the pEGFP carrier. Transfected HUVECs showed cytoplasmic green fluorescence, and the transient transfection rate was about 20.3%. Pools of G418-resistant cells exhibited a higher sensitivity to theprodrug/GCV compared to non-transfected HUVECs or non-transfected HepG2 cells, respectively. CONCLUSION: KDR promoter and the suicide gene/prodrug system mediated by diagnostic ultrasound combined with microbubble can significantly kill HUVECs. Such therapy may present a novel and attractive approach to target gene therapy on tumor vessels.

Basic fibroblast growth factor gene transfection in repair of internal carotid artery aneurysm wall

Surgery or interventional therapy has some risks in the treatment of cerebral aneurysm. We established an internal carotid artery aneurysm model by dripping elastase in the crotch of the right internal and external carotid arteries of New Zealand rabbits. Following model induction, lentivirus carrying basic fibroblast growth factor was injected through the ear vein. We found that the longer the action time of the lentivirus, the smaller the aneurysm volume. Moreover, platelet-derived growth factor expression in the aneurysm increased, but smooth muscle 22 alpha and hypertension-related gene 1 mRNA expression decreased. At 1,2, 3, and 4 weeks following model establishment, following 1 week of injection of lentivirus carrying basic fibroblast growth factor, the later the intervention time, the more severe the blood vessel damage, and the bigger the aneurysm volume, the lower the smooth muscle 22 aJpha and hypertension-related gene ~ mRNA expression. Simultaneously, platelet-derived growth factor expression decreased. These data suggest that recombinant lentivirus carrying basic fibroblast growth factor can repair damaged cells in the aneurysmal wall and inhibit aneurysm dynamic growth, and that the effect is dependent on therapeutic duration.

Effects of ribozyme targeting platelet-derived growth factor receptor β subunit gene on the proliferation and apoptosis of hepatic stellate cells in vitro

Background Activation and proliferation of hepatic stellate cells (HSC) is essentially involved in the development and progression of hepatic fibrosis. The most potent growth factor for HSC is platelet-derived growth factor receptor (PDGF) and PDGF receptor β subunit (PDGFR-β) is the predominant signal transduction pathyway of PDGF which is overexpressed in activated HSC. This study investigated the cleavage activity of hammerhead ribozyme targeting PDGFR-β mRNA in HSC and the effect on biological characteristics of HSC.Methods Expression vector of anti-PDGFR-β ribozyme was constructed and transfected into rat activated HSC with lipofectamin. The positive cell clones were gained by G418 selection. The expression of PDGFR-β, α-smooth muscle actin, and typeⅠand type Ⅲ collagen were detected by using Northern blot, Western blot and immunocytochemical staining, respectively. The cell proliferation was determined with MTT colorimetric assay. The cell apoptosis was analyzed by using flow cytometry, acridine orange fluorescence vital staining and transmission electron microscopy.Results The expression of PDGFR-β at mRNA and protein level was markedly reduced in ribozyme-transfected HSC by 49%-57% ( P <0.05-0.01). The proliferation and α-smooth muscle actin expression of ribozyme-transfected HSC were significantly decreased ( P <0.05-0.01), and the type Ⅰ and type Ⅲ collagen synthesis were also reduced ( P <0.01). In addition, the proliferative response of ribozyme-transfected HSC to PDGF BB was significantly inhibited. Otherwise, the apoptotic cells were significantly increased in ribozyme-transfected HSC ( P <0.01), and typical apoptotic cells could be found under transmission electron microscopy.Conclusions The anti-PDGFR-β ribozyme effectively cleaved the target RNA and significantly inhibited its expression, which blocked the signal transduction of PDGF at receptor level, inhibited HSC proliferation and collagen synthesis, and induced HSC apoptosis. These results suggest that inhibiting PDGFR-β expression of HSC may be a new target for the therapy of liver fibrogenesis, and ribozyme may be a useful tool for inhibiting PDGFR-β expression.